JPH11347945A - Work surface grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate wasteful use of abrasive grains, ensure the safety of operator, and provide a dust-preventive measure. SOLUTION: A work surface grinding device is composed of a working chamber 21 equipped with a storage for abrasive grains located under a processing table 22 to support a work, a grain jetting device 23 which includes an impeller formed by holding a plurality of vanes pinched by two discs and leaving the inter-vane peripheral surface open and is structured so that a belt is set on the impeller and part of the peripheral surface is closed, and a feeder 25 which feeds abrasive grains from the storage into the impeller via a cast-in port provided in one of the discs, whereby centrifugal force is given to each grain by rotating the impeller, and the grains are blown against the work upon their flying in the tangential direction to the discs passing the separating point of the belt from the impeller peripheral surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for grinding a work surface.

[0002]

Conventionally, in order to adapt a dental prosthesis into the oral cavity and make it function over a long period of time, it is necessary to accurately reproduce the shape of the oral cavity of the patient and to make the surface of the prosthesis dense and smooth. It needs to be finished in a lot. However, a dental prosthesis has a complicated uneven surface and is often manufactured by compounding a metal, a ceramic, a resin, and the like, so that it takes time and effort to grind the surface. For example, if the dental prosthesis is made of metal or ceramic, first remove the mold material and oxide layer with a rough sandpaper as a rough finish, then cut off the sprue wire with a grinder, carborundum point,
The shape is given by using diamond points, carbide bars, heatless stones and the like. Next, as a semi-finishing, it is a general practice to polish with a silicon point, sand, or the like, add a polishing material to a rotating brush such as a handpiece engine or a lathe and polish, and finally perform mirror finishing by buffing. Also, when the dental prosthesis is made of resin, after cutting off excess parts such as burrs with a stamp bar or the like, it is polished with a paper cone or sand as a medium finish, and again in the final process, it is polished by buffing. Make a delivery. As described above, in order to finally complete a dental prosthesis, it is necessary to spend considerable time and labor in a grinding or polishing process after casting.

[0003] Of these, especially in the process from semi-finishing to polishing, chips of various shapes and various grain types are prepared in order to adapt to complicated shapes such as dental prostheses. Although a smooth surface can be reliably produced by properly using them, there are the following disadvantages. In other words, spot polishing is used to mount and grind the chip in a high-speed raise, etc.It takes time and effort to process the whole as an average, and it takes time to fix the dental prosthesis and apply force to the chip. Fine adjustment is required.
Further, since a large amount of abrasive dust is generated during the operation even in the environment, there is a great problem in terms of hygiene of the operator.

[0004] Grinding or polishing is not limited to the above-mentioned dental field, and in many fields, fundamental problems such as poor workability and poor working environment cannot be fundamentally solved.

The present invention solves the above-mentioned conventional problems, and can grind or polish a complex surface to a finish in a short time, thereby maintaining a good working environment. It is intended to provide a device.

[0006]

According to the present invention, there is provided a work chamber having a storage tank for abrasive grains below a work table supporting a work, and a plurality of blades formed by two disks. A device for spraying abrasive grains with a belt wrapped around an impeller having a peripheral surface opened between the blades while being held therebetween, and an injection port provided at one of the disks in the impeller And a feeder that conveys abrasive grains from the storage tank through, and imparts a centrifugal force to the abrasive grains by rotating the impeller, in a tangential direction of a disk passing through a separation point between the impeller peripheral surface and the belt. The abrasive grains were sprayed obliquely onto the work. Further, in this configuration, the blade is formed to have a substantially triangular cross section which expands toward the outer periphery of the impeller, and a means for shortening the distance between the blades on the peripheral surface of the impeller is selectively adopted. In addition, the work room was provided with a viewing window so that the operator could perform the work while checking the grinding condition, and the manipulator and grab box ensured the safety of the workers. Here, the manipulator refers to a mechanical means that can change the direction of the work at any time, and the grab box refers to gloves built in the work room, and the glove can be operated by putting a hand in the gloves. Is defined as

Further, in the above means, the feeder is
A row in which a plurality of trays are arranged in a stepwise manner corresponding to the width of the endless belt, a plurality of rows are provided at equal intervals in the traveling direction of the endless belt, and the abrasive grains are supplied to the injection device by this configuration. It was configured to be able to supply continuously.

Furthermore, by providing a compressed air supply nozzle which opens in the direction of abrasive grain injection in parallel with the injection nozzle, especially when there is a concave portion on the work surface, the compressed air is blown to the concave portion. The accumulated abrasive grains can be promptly removed, and the grinding efficiency can be increased. On the other hand, after connecting a supply device of compressed air that opens in the direction of abrasive grain injection to the injection nozzle, a flexible tube is connected to the injection nozzle, and another nozzle is attached to the tip of the flexible tube. By means of a handpiece, grinding at an arbitrary location was made possible. In addition, by using the nozzle as a handpiece, a portion to be ground on the work surface can be specified, and grinding can be performed at an arbitrary angle.

[0009]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. First, FIG. 1 shows an embodiment of the present apparatus 20, in which 21 is a working room, 22 is a working table in a working room 21 supporting a work or a manipulator which can be remotely controlled, and 23 is An injection device for blowing abrasive grains obliquely toward the processing table 22, 2
Reference numeral 4 denotes an injection nozzle; 25, a feeder for transporting abrasive grains from a storage tank 26 provided below the processing table 22 to the injection device 23; 27, a wire mesh; and 28, which sends the abrasive grains in the storage tank 26 to the feeder 25. It is a wing car. That is, the injection device 2
After the abrasive particles sprayed from 3 collide with the work surface,
It is configured to drop into the storage tank 26 and be transported to the injection device 23 again by the feeder 25.

On the other hand, FIG. 2 shows another embodiment of the present apparatus 20, in which a glove box 29 and a viewing window 30 are provided in a work room 21, and the glove box 29 is used while watching the grinding situation from the viewing window 30. An operation such as changing the direction of a work placed on the processing table 22 can be performed.

In the above-mentioned grinding apparatus, the feeder 25 is used.
Corresponds to a belt conveyor, a screw conveyor, or the like, but a belt conveyor preferably has a configuration capable of continuously supplying abrasive grains. Specifically, as shown in FIGS. 3 and 4, three trays 4 corresponding to the width H of the endless belt 40 are provided.
1a, 41b, and 41c are arranged stepwise so as to be inclined downward to form a row R.
A plurality of rows are provided at equal intervals in the traveling direction of 0 to constitute the feeder 25. Therefore, since the supply of the abrasive grains in the next row R is started at the same time when the supply of the abrasive grains in one row R is completed, the abrasive grains can be continuously supplied to the injection device 23. In addition, the supply amount of the abrasive grains can be adjusted by adjusting the rotation speed of the endless belt, and it is needless to say that more continuous supply is possible by adjusting the gap between the rows, for example. However, in the belt conveyor, each row does not necessarily need to be configured with three trays, but may be configured with four or more trays.

Next, as shown in FIGS. 5 and 6, the detailed structure of the injection device 23 is such that a plurality of plate-like blades 31c are held between two disks 31a and 31b, And a belt 32 wound around the impeller 31 so as to close a part of the peripheral surface. Further, the blade 31c is provided to be inclined forward in the rotation direction. Then, the impeller 31 is rotated by a drive shaft 31d provided on one of the disks 31a, and an input port 31e is provided on the other disk 31b.
The abrasive grains are supplied to the inside of the impeller 31 through the supply pipe 25a. Reference numeral 33 denotes a pulley for linking the belt 32 with the impeller 31.

According to the injection device 23, the charging port 31e
The abrasive grains 10 dropped into the impeller 31 from the
c, due to the wind pressure and centrifugal force, the roller gradually shifts toward the outer periphery of the impeller 31 and further rolls on the belt 32 to form the belt 32.
Is injected in a tangential direction starting from a point away from the peripheral surface of the impeller 31.

Although the blade 31c may be plate-shaped, it may be formed in a substantially triangular cross-section expanding toward the outer periphery of the impeller 31, as shown in FIG. In this case, since the interval between the blades 31c on the peripheral surface of the impeller is reduced, the distance over which the abrasive grains 10 roll the belt 32 is correspondingly reduced, and wear of the belt 32 can be prevented. Further, since a negative pressure is generated toward the indoor side of the impeller 31, the abrasive grains 10 can be efficiently biased toward the belt 32.

In the above embodiment, the abrasive grains 10 are sprayed obliquely downward from the impeller 31.
It is also possible to spray obliquely upward by providing c in the radial direction and rotating the impeller 31 in the reverse direction. In other words, by appropriately rotating the impeller 31 in the reverse direction, the work surface can be ground from another angle without moving the work itself.

FIG. 8 shows a second embodiment of the present grinding apparatus, in which a compressed air supply nozzle 50 is provided in the direction in which the abrasive grains 10 are injected in parallel with the injection nozzle 24. It is. According to this configuration, the recess 5 is formed on the work surface W.
In the case where 1 is present, by blowing compressed air to the work surface W as appropriate, the abrasive grains 10 accumulated in the concave portion 51 are scattered to the outside, and the grinding efficiency can be increased.

FIG. 9 shows a third embodiment of the present grinding apparatus, in which a compressed air supply device 60 that opens in the direction of abrasive grain injection is connected to the injection nozzle 24. Then, the flexible tube 6 is attached to the injection nozzle 24.
1 and a nozzle 62 is attached to the tip of the flexible tube 61 to form a handpiece. According to this configuration, the workpiece can be ground at an arbitrary location according to the length of the tube 61. Further, by holding the nozzle 62 in the hand and changing its direction, the abrasive grains 10 can be sprayed on the workpiece surface W at an arbitrary angle and at the specified grinding position. At this time, since the abrasive grains 10 in the tube 61 are accelerated by the compressed air, the abrasive grains 10 can be sprayed on the work surface W without decelerating from the injection speed of the injection nozzle 24. In addition, by appropriately bending the tube 61, it is possible to adjust the injection speed of the abrasive particles 10 blown out from the nozzle 62 or to adjust the injection density.
Grinding according to the material of the work surface W can be performed.

FIG. 10 shows abrasive grains 1 used in the grinding method of the present invention.
0 is conceptually shown, and its structure has many pores 1a.
The abrasive powder 2 is made to adhere to a porous carrier 1 having the following. More specifically, the carrier 1 is soft and plastic, and more preferably, lightweight. Specifically, it is produced from natural fibers such as plant fibers, and in this embodiment, 0.1 to 10 m
A size of about m was used. On the other hand, the abrasive powder 2 selects an abrasive material according to an object to be ground. That is, a grinding material such as silicon carbide or alumina when the object to be ground is a metal, diamond powder when a ceramic is used, and alumina or iron oxide when a plastic is used is crushed to a particle size of 1 to 20 μm. When the carrier 1 is produced from plant fibers, the fat or sugar can be made to function as an adhesive when the abrasive powder 2 is adhered.

The abrasive grains 10 apply wind or heat to dry the surface of the carrier 1 to weaken the adhesiveness of the sugar and the like. Control to avoid clogging. Further, by adding water to the dried carrier 1 having reduced tackiness, the tackiness such as the sugar content can be restored, and new abrasive powder 2 can be adhered to the surface of the carrier 1 again. That is, the carrier 1 can be reused. In addition, the carrier 1 is not limited to such natural fibers, and can be artificially composed on the condition that it has the above-described physical properties.

Next, the process of grinding the work surface with the abrasive grains 10 will be described with reference to FIG. First, after the grinding fluid is mixed, the abrasive grains 10 are obliquely sprayed onto the workpiece surface W (FIG. 1).
1 (A)). Then, the abrasive grains 10 plastically deform at the same time as colliding with the work surface W, and start grinding the work surface W (see FIG. 11B). Subsequently, the abrasive grains 10 are slid on the work surface W by the lubricating action of the grinding fluid while deforming, and the work surface W is ground by the abrasive powder 2 by an amount S moved by the abrasive grains 10 (see FIG. 11C). . Then, the abrasive grains 10 repel from the workpiece surface W to finish the grinding (see FIG. 11D).

Grinding marks S on the work surface by the above-mentioned grinding method
Compared with the conventional grinding method, a sharp grinding mark S was observed at a short distance in the direction of jetting the abrasive grains 10 (from left to right in the drawing) in the grinding method of the present invention (see FIG. 12A). This is because the kinetic energy of the abrasive grains 10 is maximum at the time of collision with the workpiece surface W, and thereafter, the kinetic energy is consumed by sliding on the workpiece surface W, and the frictional force between the abrasive grains 10 and the workpiece surface W, That is, it can be inferred that the cutting force by the grinding powder 2 is weakened, and that the abrasive grains 10 are starting to repel from the work surface W due to the elasticity of the carrier 1. On the other hand, in the case of polishing by sandpaper, a grinding mark S of a fixed length and a fixed thickness appears along the polishing direction (see FIG. 12B). A lot of depressions are formed, and a pear is generated (see FIG. 12C). From this, the grinding mark by the grinding method of the present invention is located in an intermediate shape between the sandpaper polishing and the shot blasting. An effect can be obtained.

According to the grinding method of the present invention, almost the same finishing effect as that of sandpaper polishing can be obtained by adjusting the spraying amount of the abrasive grains 10 as described above. Adjusts the spraying speed of the abrasive grains 10 according to the material of the work. For example, when the surface of the work is a soft material or a brittle material, by lowering the spraying speed of the abrasive grains 10,
Excessive grinding can be eliminated, and the surface of the workpiece can be satisfactorily finished. That is, the kinetic energy of the abrasive grains 10 is adjusted by adjusting the blowing speed of the abrasive grains 10,
It is possible to adjust the frictional force of the abrasive grains 10 on the work surface, that is, the cutting force by the grinding powder 2. further,
Depending on the surface shape of the work, compressed air may be sprayed at the same time as the abrasive grains 10 are sprayed. For example, when there is a concave portion on the surface of the work, the abrasive grains 10 may accumulate in the concave portion and the grinding efficiency may decrease. However, since the abrasive grains 10 have a small specific gravity, the abrasive particles 10 accumulate in the concave portion by blowing compressed air to the concave portion. Abrasive grains 10 can be quickly removed, and the grinding efficiency can be increased. As described above, the spray amount and the spray speed of the abrasive particles 10 are appropriately adjusted, and the abrasive particles 1
Spraying compressed air on the surface of the work at the same time as spraying 0 is included in the technical scope of the grinding method according to the present invention.

[0023]

As described above in detail, in the grinding apparatus according to the present invention, the abrasive grains which have been sprayed are dropped into a storage tank and supplied again to the spraying apparatus. The operation was performed using a manipulator and a grab box, which improved safety for workers and reduced dust and improved the working environment.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the grinding apparatus of the present invention.

FIG. 2 is a side view showing another embodiment of the grinding apparatus of the present invention.

FIG. 3 is a side view showing an embodiment of the feeder.

FIG. 4 is a perspective view of the feeder.

FIG. 5 is a longitudinal sectional view showing an injection device of the grinding device of the present invention.

FIG. 6 is a side view of the injection device.

FIG. 7 is a side view showing another embodiment of the injection device.

FIG. 8 is a side view showing a second embodiment of the grinding apparatus of the present invention.

FIG. 9 is a side view showing a third embodiment of the grinding apparatus of the present invention.

FIG. 10 is a conceptual diagram showing an example of abrasive grains used in the grinding apparatus of the present invention.

FIG. 11 is a conceptual diagram showing a grinding process using the above abrasive grains.

FIG. 12 is a conceptual diagram comparing a grinding mark by the above-mentioned abrasive grains with a grinding mark by a conventional grinding method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Abrasive grain 20 Grinding device 21 Work room 22 Processing table 23 Injection device 24 Injection nozzle 25 Feeder 26 Storage tank 29 Grab box 30 Viewing window 31 Impeller 32 Belt 40 Endless belt 41a, 41b, 41c Tray 50 Compressed air supply nozzle 60 Compression Air supply device 61 Flexible tube 62 Another nozzle (handpiece)

Claims (7)

[Claims] 1. A work chamber having a storage tank for abrasive grains below a processing table for supporting a work, and a plurality of blades sandwiched between two disks to open a peripheral surface between the blades. An abrasive spraying device in which a part of the peripheral surface is closed by wrapping a belt around a car, and a feeder that conveys the abrasive from the storage tank through an inlet provided in one of the disks in the impeller. Rotating the impeller to impart centrifugal force to the abrasive grains, and spraying the abrasive grains onto the workpiece in a tangential direction of a disk passing through a separation point between the impeller peripheral surface and the belt. Grinding equipment. 2. An apparatus for grinding a work surface according to claim 1, wherein the blades have a substantially triangular cross section which expands toward the outer periphery of the impeller, and the distance between the blades on the peripheral surface of the impeller is shortened. 3. The apparatus for grinding a work surface according to claim 1, wherein a viewing window is provided in the working chamber, and a manipulator is employed in place of the processing table. 4. The apparatus for grinding a work surface according to claim 1, wherein a viewing window is provided in the working chamber, and a grab box is provided on a wall of the working chamber. 5. A feeder according to claim 1, wherein a plurality of rows in which a plurality of trays are arranged in a stepwise manner corresponding to the width of the endless belt are provided at equal intervals in the traveling direction of the endless belt. 5. The apparatus for grinding a work surface according to claim 1. 6. The apparatus for grinding a work surface according to claim 1, further comprising a compressed air supply nozzle which opens in the direction of abrasive grain injection in parallel with the injection nozzle. 7. A jet nozzle is connected to a supply device for compressed air which opens in the direction of jetting abrasive grains inside the jet nozzle, and a flexible tube is connected to the jet nozzle. The work surface grinding device according to any one of claims 1 to 5, wherein the device is a handpiece.